Thiamine formula

On more severe thionation, a third thiamine ring is formed to give a sulfur black. However, if hydroxyl groups instead of amino groups are attached at positions 2 and 2, no ring closure would take place and the blue dye would be stable to heat. These formulas are general expressions for the nuclear stmctures of the blue-to-black sulfur dyes they do not take into consideration the quinonoid formation of each dye and other aspects. 

THIAMINE (Vitamin Bi). Some earlier designations for this substance included aneurin, antmeuntic factor, antibenben factor, and oryzamin. Thiamine is metabolically active as thiamine pyrophosphate (TPP). the formula of which is ... 

Recoveries 102% for thiamine and riboflavin from infant formula 101% for pyridoxine from infant formula. 

A standard reference material for infant formula has also been certified for vitamin C, riboflavin, niacin, and pyridoxine (197). Another recent study (198) indicated that off-the-shelf wheat germ is suitable for use as a secondary reference material for thiamine and niacin riboflavin was also evaluated but found to be somewhat unstable over time. Powdered orange drink was deemed suitable as a secondary reference material for vitamin C. 

GW Chase, WO Landen, RR Eitenmiller, A-GM Soliman. Liquid chromatographic determination of thiamine, riboflavin, and pyridoxine in infant formula. J AOAC Int 75 561-565, 1992. 

Common Name Aneurine Bl-Vitamin Oryzanin Thiamine chloride Torulin Structural Formula ... 

Assay Determine as directed in the monograph for Thiamine Hydrochloride. Calculate the quantity, in milligrams, of C12H17N504S in the sample taken by the formula... 

This vitamin acts as a coenzyme in the metabolism of carbohydrates and is present in all living tissues. It acts in the form of thiamin diphosphate in the decarboxylation of a-keto acids and is referred to as cocarboxylase. Thiamin is available in the form of its chloride or nitrate, and its structural formula is shown in Figure 9-12. The molecule contains two basic nitrogen atoms one is in the primary amino group, the other in the quater-... 

Figure 9-12 Structural Formula of Thiamin. Hydrochloride X = Cl, HC1 Mononitrate X = N03. ...

Woollard, D.C. and Indyk-Harvey, E. Rapid determination of thiamine, riboflavin, pyri-doxine, and niacinamide in infant formulas by hquid chromatography. J. AOAC Int. 2002, 85,945-951. 

Thiamine, Vitamin has the following formula (that sho vn is for thiamine chloride) ... 

Use Medicine, nutrition, enriched flours. Isolated usually as the chloride (see formula above). Available as thiamine hydrochloride and thiamine mononitrate. 

Infantile WE may be found in developing conntiies, primarily among breast-fed infants, nsnally in the second to fifth months of development. Wernicke s encephalopathy is very rare in developed nations. However, in 2003, Israel was faced with an epidemic of WE dne to a batch of defective soy-based vegetarian infant formula. WE was documented in 20 ont of an estimated 3500 infants who were fed the formula, later found to be deficient in thiamine (Kesler et al., 2005). 

Kesler, A., Stolovitch, C., Hoffmann, C., Avni, 1., and Morad, Y. (2005). Acute ophthalmoplegia and nystagmus in infants fed a thiamine-deficient formula an epidemic of Wernicke encephalopathy. J. Neuroophthalmol. 25 169-172. 

The UPLC-MS/MS method has also been developed for fast simultaneous separation and determination of 14 different water-soluble vitamins and vitamin-like compounds in infant formula (thiamine, riboflavin, pantothenic acid, nicotinic acid, nicotinamide, pyridoxine, pyridoxal, biotin, fohc acid, cyanocobalamin, ascorbic acid, L-camitine, choline, and taurine) [91], Methotrexate was also used as an internal standard for riboflavin, cyanocobalamin, biotin, and folic acid, while nicotinamide was used as an internal standard for the other compounds. 

A case of thiaminase disease due to a fungus has been reported. The agent was Trichosporon aneurolyti-cum which grew in the patient s mouth. Experimentally, the administration of thiamine analogs, such as pyrithiamine and oxythiamine, may also produce thiamine deficiency. The mechanism by which they act is discussed later (see formulas in Fig. 4-5). 

The thiamine molecule contains two cyclic rings—a pyrimidine and a thiazolium—linked by a methylene group and carrying side chains to make the formula 3,4-amino-2-methylpyrimidyl-5-methyl - 4 - methyl - 5 -hydroxyethyl thiazolium hydrochloride. 

Structural formula of thiamin and its chemical properties. (A) Structural formula of thiamin. (B) The C-2 carbon of the thiazolium moiety can lose its proton yielding a highly nucleophilic ylide analogous to cyanide. (C) Cyanide and thiamin catalysed condensation of benzaldehyde to benzoin. (D) Oxydation of thiamin in strongly alkaline medium yields the highly fluorescent thiochrome, a property used for the experimental determination of thiamin and its phosphate esters. 

Figure 5.4 Structural formulae of thiamin phosphate esters. At present, five natural thiamin phosphate derivatives have been described thiamin monophosphate (ThMP) thiamin diphopshate (ThDP) thiamin triphosphate (ThTP) adenosine thiamin diphosphate (AThDP) and adenosine thiamin triphosphate (AThTP). Catalytic intermediates, such as for instance a-hydroxyethyl thiamine diphosphate formed by the action of yeast pyruvate decarboxylase (EC 4.1.1.1), are not considered here.

Fattal-Valevski, A., Kesler, A., Sela, B.A., Nitzan-Kaluski, D., Rotstein, M., Mesterman, R., Toledano-Alhadef, H., Stolovitch, C., Hoffmarm, C., Globus, O., and Eshel, G., 2005. Outbreak of life-threatening thiamine deficiency in infants in Israel caused by a defective soy-based formula. Pediatrics. 115 e233-238. 

AOAC 986.27 Thiamine in milk-based infant formula—fluorometric method Infant formula AOAC 1990d... 

The recently elaborated multivitamin methods for B vitamins assay using LC with MS/MS detection, micellar LC, LC-DAD/MS, LC/ESI-MS or LC-IDMS systems offer better sensitivity and selectivity, and can be potentially used for thiamine determination in fortified foods and infant formulas. These methods have potential to improve performance in the future. 

Assays of thiamine in food, fortified food, infant formulas and premixes are based on microbiological and chemical methods. 

AO AC, 1990d. Method 986.27. Thiamine in milk-based infant formula— fluorometric method Final action. In Official Methods of Analysis of the Association of Official Analytical Chemists, 15th ed. Association of Official Analytical Chemists, Arlington VA, USA, pp. 1113-1114. 

Thiamine chloride hydrochloride, the form in which the vitamin is usually isolated or prepared, has the empirical formula C12H18N4OSCI2 and structure... 

The structure of cocarboxylase (see Fig. 1 for formula) was established by Lohmann and Schuster. A long-established function of cocarboxylase (thiamine pyrophosphate, aneurin) is as the coenzyme of a-ketoaeid carboxylase. Mg++ is also required. The reaction involved is the nonoxidative decarboxylation of an a-keto acid to CO2 and an aldehyde with one less carbon atom. The most important example is the splitting of pyruvic acid to acetaldehyde and CO2 (equation 9). This... 

Upon addition of 2 moles of alkali to thiamine hydrochloride the quaternary thiazole ring opens to form an acidic sulfhydryl group. This isomeric sulfhydryl form, as well as the disulfide form of both thiamine and TPP, have been prepared. The formula of the sulfhydryl form of TPP is the following ... 

In thiamine deficiency, pyruvate accumulates in the blood and tissues and there is a change in the lactate-pyruvate ratio. These findings have been used in detecting thiamine deficiency in man. MIorwitt has proposed as a test of thiamine nutrition the simultaneous measurement of lactic acid, pyruvic acid, and glucose in the blood 5 min. after mild exercise and 60 min. after ingestion of glucose. The carbohydate index (C.I.) is determined from the formula... 

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